Haruhi Fujioka is a scholarship student at the prestigious Ouran Academy, a fictitious high school located in Bunkyo, Tokyo. Looking for a quiet place to study, Haruhi stumbles upon the Third Music Room, a place where the Ouran Academy Host Club, a group of six male students, gathers to entertain female "clients." During their initial encounter, Haruhi accidentally knocks over and breaks an antique vase valued at ¥8,000,000 (US$80,000 in the U.S. English manga)[1] and is told to repay the cost in service to the club as an errand boy. Haruhi's short hair, slouching attire and gender-ambiguous face cause her to be mistaken by the hosts for a male student. After a brief run as such, the Hosts soon realize that she's a "natural" in entertaining girls and promote her to full-Host status.[2] She agrees since Hosting will help her pay off her debt more quickly. The members of the club discover her true gender one by one, but they keep this fact a secret.

Ouran Elite Academy encompasses pre-school through high school and has an attached university program. Most students come from elite families, but a scholarship is annually awarded to the top scorer on a rigorous entrance examination. Haruhi is such a student for her grade level. The school's unofficial motto is "Lineage counts first, wealth a close second," meaning students with stellar family backgrounds but low socioeconomic status may be given top priority over those from rich families with lesser pedigrees.

Other than Haruhi, the other members of the Host Club include President Tamaki Suoh, Vice-president and "Shadow King" Kyoya Ootori; Hikaru and Kaoru Hitachiin, identical 1st-year twins; Mitsukuni "Honey" Haninozuka and his cousin Takashi "Mori" Morinozuka. Tamaki is the charming, beautiful hafu and top draw of the club with a 70% request rate, thus earning him the title of "King." Kyoya, however, is the "Shadow King," the true director who runs the show from behind the scenes with a charming facade and gracious manners. The Hitachiin twins, who share classes with Haruhi, are mischievous imps who utilize a devised brotherly love angle on their relationship to captivate their guests. Honey is from a distinguished martial arts family, but plays the role of a "boy Lolita" who has a great passion for stuffed animals and sweets while Mori is his tall, quiet protector with a fierce appearance and soft heart. All the characters are parodies of shojo manga characters, with Haruhi serving as the "natural" type, Tamaki as the "princely" type, Kyoya as the "cool" type, the Hitachiin twins as the "little devils" or "mischievous" type, Honey as the "Boy Lolita" type, and Mori as the "strong, silent type."

Love interests include mainly Tamaki Suoh, who has taken up the role of 'father' in the group, often referring to Haruhi as his 'daughter'. The other members excluding Haruhi feel this is Tamaki's way of protecting the ideal friendship/family he has created with them, therefore portraying his feelings he has for her as one a father must feel for a daughter instead of romantic feelings that could hurt the dynamic of the group (often he is not aware of his own feelings, it could be a way of protecting himself as well as the group). The Hitachiin twins also have a strong friendship with Haruhi, as Haruhi was one of the first people to get to know them as individual people and being able to tell them apart, allowing her to be 'a part of their world'. Hikaru soon learns that perhaps his feelings for Haruhi are more than just of friendship and he soon tries to pursue her romantically. Haruhi often gets depressed when she realizes someone has an interest in her and she could not pick it up. She plays a clueless character when it comes to romantic love. She is often clueless about her own feelings too, yet becomes open to exploring them and experiencing life with her friends.

The Ouran High School Host Clubmanga was serialized in Japan between the September 2002 and November 2010 issues of LaLa.[3] The individual chapters were collected in 18 tankōbon volumes between August 5, 2003 and April 5, 2011.[4][5] Hakusensha released a fanbook for the series on August 4, 2009 titled Ōran Kōkō Hosuto Kurabu Fanbukku: Uki Doki Kōryaku Daisakusen(桜蘭高校ホスト部(クラブ)ファンブック～うきドキ☆攻略大作戦～?).[6] The series is licensed in English North America by Viz Media under its Shojo Beat imprint, and in Indonesia in the monthly manga magazine Hanalala. It is published in Singapore (in both simplified Chinese and English) by Chuang Yi, and in Poland by JPF.[7]

The series is licensed for distribution in North America by Funimation Entertainment. Caitlin Glass is the ADR director of the series. The first anime DVD set containing the first thirteen episodes was released on October 28, 2008 in North America.[8] The second volume containing the last thirteen episodes was released on January 6, 2009. On April 27, 2009, the series made its North American television debut on the Funimation Channel.[9]

Three drama CDs were released in 2003, as well as two tracks included in LaLa magazine's 28th and 29th anniversary CDs. Three soundtracks were released by Video and Audio Project for the Ouran High School Host Club anime adaptation. The first, Ouran High School Host Club Soundtrack & Character Song Collection (Part 1)(桜蘭高校ホスト部サントラ&キャラソン集 <<前編>>?), was released in Japan on July 26, 2006 and contained twenty tracks, including the anime opening theme song. The second, Ouran High School Host Club Soundtrack & Character Song Collection 2(桜蘭高校ホスト部サントラ&キャラソン集 <<後編>>?), contained an additional nineteen tracks and was released on August 23, 2006. On September 20, 2007, a third soundtrack, the Ouran High School Host Club Soundtrack & Character Song Collection Special Edition(桜蘭高校ホスト部 サントラ&キャラソン集《特別編》?) was released containing eight songs from the previous two tracks, with four additional songs.

The Ouran Host Clubvisual novel was released for PlayStation 2 on April 19, 2007 by Idea Factory.[10] Based on the television series, the player makes decisions as Haruhi that affect the other hosts feelings toward her. The game features the characters of Jean-Pierre Léo, a longtime French friend of Tamaki, and Sayuri Himemiya, a childhood friend of Haruhi, designed by the series creator. There are two other original characters. The game has been released exclusively in Japan. A Nintendo DS port of the game, updated with a fully voiced cast and new character-specific scenarios, was released on March 19, 2009.[11]

A live-action film of Ouran was announced during a fan meeting on August 25, 2011 and continues off from the conclusion of the television series. All actors of the live-action television series reprised their roles. The film was released on March 17, 2012.[13][14] It was released on DVD and Blu-ray Disc on October 10, 2012.

The series had a spin-off named Ouran High School Host Club: Haruhi no Happy Birthday Daisakusen(桜蘭高校ホスト部 〜ハルヒのハッピーバースデー大作戦〜?) with the same cast that was originally broadcast on January 6, 2012 by LISMO drama, a mobile drama provided by au. This LISMO drama tells an original story worked on by the author of the manga. The drama revolves around the host club members becoming flustered upon learning that it is Haruhi’s birthday. Through their misunderstandings about celebrating her birthday, the members make Haruhi angry. Kawaguchi, who plays Haruhi Fujioka, commented, "You will see an explosion of this well-known bright and silly character! It was fun playing the role, and all the host club members enjoyed the filming." Each episode is approximately five minutes long, and there are four episodes.[15]

According to Tania Darlington in a paper published by the University of Florida, the series is a parody of otaku culture, especially cross-dressing, yaoi and yuri cultures within otaku culture. The club often dresses up in flamboyant costumes, and Renge Hōshakuji is also identified as an otaku.[16]